Author Archives: statswithcats

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About statswithcats

Charlie Kufs has been crunching numbers for over forty years. He retired in 2019 and has published Stats with Kittens, for people interested in statistics who have not yet taken Stats 101, and the second edition of Stats with Cats, for people who have taken Stats 101 and want to use statistics at work or in their life.

The Right Tool for the Job

Posted on August 27, 2010 by statswithcats

Statistics are like power tools. If you know how to use them, they are incredibly valuable and fun to use. They help you do your job better, more thoroughly, and more quickly. But if you are careless, they can cause … Continue reading →

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The Five Pursuits You Meet in Statistics

Posted on August 22, 2010 by statswithcats

When people think about statistical analyses, they often think only of mind-numbing number crunching that creates yet more numbers. But that’s like touring a cabinetmaker’s shop and seeing only the sawdust. A talented cabinetmaker can create beauty and function in … Continue reading →

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Time Is On My Side

Posted on August 15, 2010 by statswithcats

If you do much data analysis it won’t be long before you work with data measured over a range of times. When you do see time-series data, you’ll find that time scales and time units have some very quirky properties. … Continue reading →

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The Zen of Modeling

Posted on August 8, 2010 by statswithcats

What’s the first thing you think of when you hear the word model? The plastic model airplanes you used to build? A fashion model? The model of the car you drive? The person who is your role model? But what … Continue reading →

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There’s Something About Variance

Posted on August 1, 2010 by statswithcats

Imagine practicing hitting a target using darts, bow and arrow, pistol, cannon, missile launcher, or whatever. You aim for the center of the target. If your shots land where you aimed, you are considered to be accurate. If all your … Continue reading →

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Samples and Potato Chips

Posted on July 26, 2010 by statswithcats

Samples are like potato chips. You’re never satisfied with just one. Every one you take makes you want more. And you’re never sure you’ve had enough until you’ve had way too many.   Betcha Can’t Take Just One One observation. … Continue reading →

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Purrfect Resolution

Posted on July 17, 2010 by statswithcats

No matter what their area of expertise, statisticians are asked certain questions with such predictability that it borders on the deterministic. No question is asked more often than: How many samples do I need? Most statisticians wish they could answer … Continue reading →

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30 Samples. Standard, Suggestion, or Superstition?

Posted on July 11, 2010 by statswithcats

If you’ve ever taken any applied statistics courses in college, you may have been exposed to the mystique of 30 samples. Too many times I’ve heard statistician do-it-yourselfers tell me that “you need 30 samples for statistical significance.” Maybe that’s … Continue reading →

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It’s All Greek

Posted on July 3, 2010 by statswithcats

When Humpty Dumpty uses a word, it means just what he chooses it to mean, neither more nor less. To people not conversant in a technical specialty, it seems that all the experts are Humpty Dumptys. Statistics is no exception. … Continue reading →

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Weapons of Math Production

Posted on June 27, 2010 by statswithcats

In theory, if you have the free time, you can calculate any statistic you might need using nothing more than a pencil and paper. After all, it’s just matrix mathematics. With a lot of data or a complicated procedure, though, … Continue reading →

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